Screening checklist
Backend Developer Screening Checklist
Screen backend developer candidates with this checklist covering API design, database skills, system architecture, security practices, and scoring rubrics.
The short answer
Screening Backend Developer candidates well means fixing the pass criteria before the first résumé is opened. The checklist below covers résumé triage, a short phone screen with model answers, a technical check with passing criteria, and the deal-breakers that end a conversation early.
- Must have: Solid understanding of software architecture patterns including microservices, event-driven, and monolithic designs
- Must have: Experience with database design, indexing strategies, and query performance optimization
- Must have: Proficiency in API design with attention to versioning, authentication, and error handling
- Deal-breaker: Cannot explain fundamental backend concepts like database indexing, API authentication, or caching
Cohesyve scores every applicant against a role-specific assessment. Ten candidates free, no card.
Backend developers build the server-side logic, APIs, and data infrastructure that power applications behind the scenes. Screening for this role demands evaluating database expertise, API design skills, system architecture thinking, and security awareness. This checklist ensures you identify candidates who can build robust, scalable backend systems that meet your product requirements.
Résumé screening
- Minimum two years of professional backend development experience
- Proficiency in at least one server-side language such as Python, Java, Node.js, Go, or C#
- Strong experience with relational databases like PostgreSQL or MySQL and query optimization
- Familiarity with NoSQL databases such as MongoDB, Redis, or DynamoDB for appropriate use cases
- Experience designing and building RESTful or GraphQL APIs
- Knowledge of cloud services, containerization, and deployment practices
Must-have qualifications
- Solid understanding of software architecture patterns including microservices, event-driven, and monolithic designs
- Experience with database design, indexing strategies, and query performance optimization
- Proficiency in API design with attention to versioning, authentication, and error handling
- Knowledge of security best practices including input validation, encryption, and authentication protocols
- Experience with automated testing including unit, integration, and API testing
Phone screen questions
Ask every candidate the same set, in the same order, and note the answer against the model before you form a view.
Describe a backend system you designed or significantly improved. What were your key architectural decisions?
A strong answer The candidate should describe the system requirements, their architectural choices, the trade-offs considered, and the outcomes in terms of performance, scalability, or reliability. They should demonstrate thoughtful decision-making and ability to balance competing concerns.
How do you approach database schema design for a new feature?
A strong answer A strong answer covers understanding data requirements, normalizing the schema appropriately, planning for indexes and query patterns, considering data growth, and migrating schema changes safely. The candidate should show awareness of both relational and non-relational approaches.
Tell me about a performance bottleneck you identified and resolved in a backend system.
A strong answer The candidate should describe how they identified the bottleneck using profiling or monitoring tools, the root cause, the solution implemented, and the performance improvement achieved. They should demonstrate systematic debugging and measurement-driven optimization.
How do you handle authentication and authorization in APIs you build?
A strong answer The candidate should discuss authentication mechanisms like JWT or OAuth, role-based access control, input validation, rate limiting, and secure session management. They should demonstrate understanding of common security vulnerabilities and how to prevent them.
What is your approach to error handling and logging in backend services?
A strong answer The candidate should describe structured error handling with meaningful error codes and messages, centralized logging with appropriate log levels, correlation IDs for tracing requests across services, and monitoring alerts for critical errors. They should show a production-ready mindset.
Cohesyve
Let the screen run itself
Cohesyve puts a Backend Developer assessment between the application and the phone screen, so the calls you make are with people who have already cleared the bar above.
Technical screening
| Area | What to test | Passing criteria |
|---|---|---|
| API Design | Ask the candidate to design a RESTful or GraphQL API for a given feature including endpoints, request and response schemas, authentication, and error handling. | The API design follows best practices with consistent naming, proper HTTP methods, meaningful status codes, and thoughtful error responses. The candidate considers pagination, versioning, and rate limiting. |
| Database Design and Querying | Provide a business scenario and ask the candidate to design a database schema, write complex queries, and discuss indexing strategies. | The schema is well-normalized, supports required query patterns efficiently, and includes appropriate constraints and indexes. Queries are correct, optimized, and the candidate explains their performance characteristics. |
| System Architecture | Present a scalability challenge and ask the candidate to design a backend architecture that handles high throughput, data consistency, and fault tolerance. | The candidate identifies appropriate architectural patterns, discusses trade-offs between consistency and availability, proposes caching and queuing strategies, and considers monitoring and failover mechanisms. |
| Code Quality and Testing | Ask the candidate to implement a backend feature or fix a bug in a provided codebase. Evaluate code quality, testing approach, and handling of edge cases. | Code is well-structured, follows SOLID principles, includes appropriate error handling, and is accompanied by meaningful tests. The candidate demonstrates clean coding practices and attention to edge cases. |
Fit and deal-breakers
Good signs
- Shows passion for building reliable, well-architected systems
- Demonstrates willingness to collaborate with frontend developers and product teams
- Values code quality, testing, and documentation as part of the development process
- Exhibits curiosity about new technologies while maintaining pragmatism about adoption
- Takes ownership of production systems and participates in on-call or incident response willingly
Deal-breakers
- Cannot explain fundamental backend concepts like database indexing, API authentication, or caching
- Writes code without considering error handling, security, or edge cases
- Shows no experience with testing or dismisses its importance
- Demonstrates inability to think about system scalability or performance
Scoring rubric
Technical Proficiency
35%- Demonstrates strong skills in server-side programming and framework knowledge
- Designs efficient database schemas and writes optimized queries
- Builds well-designed APIs following industry best practices
Architecture and Scalability
25%- Designs systems that scale gracefully under increasing load
- Makes informed trade-offs between consistency, availability, and performance
- Understands caching, queuing, and distributed system patterns
Security and Reliability
20%- Implements security best practices in authentication, authorization, and data handling
- Builds robust error handling and monitoring into backend services
- Writes comprehensive tests and maintains high code quality standards
Collaboration and Culture
20%- Communicates architectural decisions clearly to team members and stakeholders
- Collaborates effectively with frontend, DevOps, and product teams
- Aligns with team values and contributes to a positive engineering culture
Common questions
Should we screen for a specific backend language or framework?
If your team uses a specific language heavily, verify proficiency in it. However, strong computer science fundamentals and experience with any server-side language transfer well. A great developer who knows Python can learn Go or Java relatively quickly if they have solid architectural understanding.
How do we assess database skills during screening?
Include practical exercises that require schema design, writing complex SQL queries, and discussing indexing strategies. Present a realistic scenario rather than textbook questions. Also ask about their experience with database migrations, backups, and handling data growth.
What is the difference between screening a backend developer and a full-stack developer?
Backend developer screening should go deeper into server-side architecture, database optimization, and infrastructure concerns. Full-stack screening balances breadth across both frontend and backend but may accept less depth in each area. Align your screening with the actual work the person will do.
Cohesyve · Skill assessments for hiring
Assess Backend Developer candidates before you interview them
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